Javier E. Ferrer, 41, pleaded guilty to a charge of conspiracy to commit criminal copyright infringement in U.S. District Court in Virginia.

Prosecutors charged Ferrer in September with being in a ring of bootleggers known as the IMAGiNE Group. He admitted that he used a video camera to secretly record films in theaters.

Another member of the group, Gregory A. Cherwonik, 53, of Canandaigua, N.Y., admitted to using an audio receiver to record the sound. Ferrer then used a computer to synchronize the audio and video. The files were then shared over the internet.

A representative from the Motion Picture Association of America said the ring was the most prolific piracy group on the internet from 2009 to 2011.

Ferrer faces up to five years in prison. He will be sentenced March 14.

Cherwonik also pleaded guilty and was sentenced to three years in prison. Three other men also have pleaded guilty. Two have been sentenced to prison and a third is also awaiting sentencing.